rs199472800

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM5PP3_StrongPP5_Very_Strong

The NM_000218.3(KCNQ1):c.1664G>A(p.Arg555His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000217 in 1,566,228 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R555C) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000023 ( 0 hom. )

Consequence

KCNQ1
NM_000218.3 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:9O:1

Conservation

PhyloP100: 7.52

Variant links:

Genes affected

KCNQ1 (HGNC:6294): (potassium voltage-gated channel subfamily Q member 1) This gene encodes a voltage-gated potassium channel required for repolarization phase of the cardiac action potential. This protein can form heteromultimers with two other potassium channel proteins, KCNE1 and KCNE3. Mutations in this gene are associated with hereditary long QT syndrome 1 (also known as Romano-Ward syndrome), Jervell and Lange-Nielsen syndrome, and familial atrial fibrillation. This gene exhibits tissue-specific imprinting, with preferential expression from the maternal allele in some tissues, and biallelic expression in others. This gene is located in a region of chromosome 11 amongst other imprinted genes that are associated with Beckwith-Wiedemann syndrome (BWS), and itself has been shown to be disrupted by chromosomal rearrangements in patients with BWS. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Aug 2011]

KCNQ1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_000218.3

PM5

Other missense variant is known to change same aminoacid residue: Variant chr11-2776032-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 3126.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.99

PP5

Variant 11-2776033-G-A is Pathogenic according to our data. Variant chr11-2776033-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 53003.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr11-2776033-G-A is described in Lovd as [Pathogenic]. Variant chr11-2776033-G-A is described in Lovd as [Likely_benign]. Variant chr11-2776033-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNQ1	NM_000218.3 linkuse as main transcript	c.1664G>A	p.Arg555His	missense_variant	13/16	ENST00000155840.12

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNQ1	ENST00000155840.12 linkuse as main transcript	c.1664G>A	p.Arg555His	missense_variant	13/16	1	NM_000218.3	P1	P51787-1
KCNQ1	ENST00000335475.6 linkuse as main transcript	c.1283G>A	p.Arg428His	missense_variant	13/16	1			P51787-2
KCNQ1	ENST00000496887.7 linkuse as main transcript	c.1307G>A	p.Arg436His	missense_variant	13/16	5
KCNQ1	ENST00000646564.2 linkuse as main transcript	c.1124G>A	p.Arg375His	missense_variant	8/11

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152214

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000227

AC:

AN:

176120

Hom.:

AF XY:

0.0000215

AC XY:

AN XY:

93168

show subpopulations

Gnomad AFR exome

AF:

0.0000931

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000410

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000233

AC:

AN:

1414014

Hom.:

Cov.:

AF XY:

0.0000229

AC XY:

AN XY:

698562

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000267

Gnomad4 SAS exome

AF:

0.0000125

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000257

Gnomad4 OTH exome

AF:

0.0000510

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152214

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74364

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000483

Hom.:

Bravo

AF:

0.00000756

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:9Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Oct 21, 2022	Published functional studies demonstrate a damaging effect as this variant results in abnormal potassium channel function (Dvir et al., 2014; Aromolaran et al., 2014); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 19716085, 23098067, 23130128, 26745405, 25705178, 22581653, 34505893, 34697415, 25037568, 19841300, 15840476, 14998624, 22949429, 27761162, 26412604, 9386136, 30609406, 32048431, 32383558, 31006312, 33087929, 25344363) -
Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jan 01, 2023	KCNQ1: PM1, PM2, PM5, PS4:Moderate, PP3, PP4, PS3:Supporting -
Pathogenic, criteria provided, single submitter	clinical testing	Kariminejad - Najmabadi Pathology & Genetics Center	Jul 10, 2021	- -

Long QT syndrome

Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 22, 2024	This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 555 of the KCNQ1 protein (p.Arg555His). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individuals with long QT syndrome (PMID: 14998624, 22949429, 23098067, 23130128). ClinVar contains an entry for this variant (Variation ID: 53003). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt KCNQ1 protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects KCNQ1 function (PMID: 25037568, 25344363). This variant disrupts the p.Arg555 amino acid residue in KCNQ1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9386136, 19934648). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jan 16, 2024	Variant summary: KCNQ1 c.1664G>A (p.Arg555His) results in a non-conservative amino acid change located in the Potassium channel, voltage dependent, KCNQ, C-terminal domain (IPR013821) of the encoded protein sequence. This alters a highly conserved residue (HGMD) in which another missense variant (p.Arg555Cys) is classified as pathogenic. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.3e-05 in 176120 control chromosomes (gnomAD). c.1664G>A has been reported in the literature in multiple individuals affected with Long QT Syndrome (e.g. Lupoglazoff_2004, Giudicessi_2012, Yee_2022). These data indicate that the variant is very likely to be associated with disease. Publications report experimental evidence evaluating an impact on protein function, finding that the variant disrupts channel current (Ademuyiwa_2014, Dvir_2014). The following publications have been ascertained in the context of this evaluation (PMID: 14998624, 22949429, 25344363, 25037568, 36102233). ClinVar contains an entry for this variant (Variation ID: 53003). Based on the evidence outlined above, the variant was classified as pathogenic. -

Long QT syndrome 1

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Molecular Genetics Laboratory - Cardiogenetics, CHU de Nantes

Aug 01, 2023

- -

Beckwith-Wiedemann syndrome;C1837014:Atrial fibrillation, familial, 3;C1865019:Short QT syndrome type 2;C4551509:Jervell and Lange-Nielsen syndrome 1;C4551647:Long QT syndrome 1

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 16, 2021

- -

Cardiovascular phenotype

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 21, 2023

The p.R555H variant (also known as c.1664G>A), located in coding exon 13 of the KCNQ1 gene, results from a G to A substitution at nucleotide position 1664. The arginine at codon 555 is replaced by histidine, an amino acid with highly similar properties. This alteration has been detected in individuals reported to have long QT syndrome (LQTS), and in several LQTS testing cohorts, although clinical details were limited (Lupoglazoff JM et al. J. Am. Coll. Cardiol., 2004 Mar;43:826-30; Tester DJ et al. Heart Rhythm, 2005 May;2:507-17; Kapplinger JD et al. Heart Rhythm, 2009 Sep;6:1297-303; Giudicessi JR et al. Circ Cardiovasc Genet, 2012 Oct;5:519-28; Stattin EL et al. BMC Cardiovasc Disord, 2012 Oct;12:95). Functional studies by different investigators have demonstrated reduced current, slower activation, and faster deactivation with this alteration, while conclusions about possible trafficking defects were conflicting (Dvir M et al. J. Cell. Sci., 2014 Sep;127:3943-55; Aromolaran AS et al. Cardiovasc. Res., 2014 Dec;104:501-11). Based on internal structural analysis, this variant is predicted to be structurally disruptive (Long SB et al. Nature. 2007 Nov;450(7168):376-82; Ambry internal data). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Cardiac arrhythmia

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Oct 30, 2023

This missense variant replaces arginine with histidine at codon 555 of the KCNQ1 protein. This variant is found within a highly conserved region of the C-terminal cytoplasmic domain of the KCNQ1 protein (a.a. 509-575). Rare nontruncating variants in this region have been shown to be significantly overrepresented in individuals with long QT syndrome (PMID: 32893267). Functional studies have shown that this variant impairs potassium channel function without disrupting protein trafficking to the cell surface (PMID: 25037568, 25344363). This variant has been reported in over ten individuals affected with long QT syndrome (PMID: 14998624, 19841300, 22949429, 23130128, 32383558, 34505893, 36102233, 37457655, ClinVar SCV000234515.13) and in another few individuals suspected of having long QT syndrome (PMID: 15840476, 19716085, 23098067, 26412604). This variant has been identified in 4/176120 chromosomes in the general population by the Genome Aggregation Database (gnomAD). A different missense variant occurring at the same codon, p.Arg555Cys, is known to be pathogenic (ClinVar variation ID 3126), indicating that arginine at this position is important for KCNQ1 protein function. Based on the available evidence, this variant is classified as Likely Pathogenic. -

Congenital long QT syndrome

Other:1

not provided, no classification provided

literature only

Cardiovascular Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust

This variant has been reported as associated with Long QT syndrome in the following publications (PMID:14998624;PMID:15840476;PMID:19716085;PMID:19841300;PMID:15214551). This is a literature report, and does not necessarily reflect the clinical interpretation of the Imperial College / Royal Brompton Cardiovascular Genetics laboratory. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.98

CardioboostArm

Pathogenic

1.0

BayesDel_addAF

Pathogenic

0.56

BayesDel_noAF

Pathogenic

0.57

Cadd

Pathogenic

Dann

Pathogenic

1.0

DEOGEN2

Pathogenic

0.99

D;.;.

Eigen

Pathogenic

0.77

Eigen_PC

Pathogenic

0.67

FATHMM_MKL

Uncertain

0.92

LIST_S2

Pathogenic

0.98

D;D;D

M_CAP

Pathogenic

0.94

MetaRNN

Pathogenic

0.99

D;D;D

MetaSVM

Pathogenic

0.90

MutationAssessor

Pathogenic

3.1

M;.;.

MutationTaster

Benign

1.0

D;D

PrimateAI

Pathogenic

0.83

PROVEAN

Uncertain

-4.4

D;.;D

REVEL

Pathogenic

0.92

Sift

Pathogenic

0.0

D;.;D

Sift4G

Pathogenic

0.0

D;.;D

Polyphen

1.0

D;.;D

Vest4

0.99

MutPred

0.96

Loss of MoRF binding (P = 0.0076);.;.;

MVP

0.99

MPC

1.3

ClinPred

0.99

GERP RS

3.8

Varity_R

0.85

gMVP

0.99

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over